This application is related to Document Disclosure No. 434055, filed Apr. 1, 1998.
Not Applicable.
This invention relates to telephone call screening units, and, in particular, to a call screening unit which automatically allows calls through which have a valid carrier signal.
Households get numerous harassing or threatening calls as well as calls from telemarketers, sales people, pollsters, etc. who try and sell the consumer any number of different types of things. These calls usually come at inconvenient times, typically during meal time. Further, such callers often let the phone ring only once or twice, which is generally not enough time to answer the phone.
Normal telephone calls have a valid carrier signal that can be easily traced to a specific number, using, for example, Caller ID(trademark) equipment. Other types of phone calls do not have a valid carrier signal. Calls that do not have a valid carrier signal appear as xe2x80x9cout-of-area, private, or anonymousxe2x80x9d calls. Additionally, calls from mobile phones, non-compatible telephone services and/or systems, and callers using a call forwarding function or a *67 prefix (the anonymous calling prefix) also have invalid signals. Most calls from telemarketers, pollsters, sales people, etc. are either private, anonymous, or out-of-area, and hence have invalid carrier signals.
Currently, if a user screens incoming calls, he can use his answering machine by listening to the message the caller leaves when the answering machine answers the phone. If the user wants to accept the call, he can pick up the phone before the caller hangs up. However, sometimes the caller does not give the user enough time to pick up the phone. Additionally, telemarketers, sales people, pollsters, etc. will usually not let the phone ring more than a few times or will not leave a message. Also, the answering machine may not be in a convenient area, and it may be difficult for the user to hear the caller""s message. This all makes it almost impossible to effectively screen incoming telephone calls.
There are several call screening devices currently available. One such device is sold by TeleScreen Inc. of Los Angeles, Calif. under the name TeleScreen. The TeleScreen device, like many of the other call screening devices that have been developed, pre-empt all phone calls, including phone calls from friends, relatives, etc. that the user would normally want to pass through. This is obviously undesirable. It is desirable to allow through local calls, such as calls from friends, family, school, or emergency personnel, so that such callers need not enter an override code for their call to pass through.
Briefly stated, the call screening unit of the present invention is interposed between the telephone itself and the wall jack. When an incoming call is received, the call screening unit initially grabs the signal without allowing the signal to pass through to the phone. The call screening unit examines the signal of the incoming call to determine if it has a valid carrier signal. If the call has a valid carrier signal, the call is allowed to pass through, and the user""s phone rings. If the incoming phone call has an invalid carrier signal, the person placing the call is prompted to enter a valid override code. The override code entered is compared with a series of user stored override codes. If a valid override code is entered, then the call is allowed through, and the phone rings. If a valid override code is not entered, then the call is terminated, and the phone never rings. The call screening unit includes a fax switch which can be set to be xe2x80x9conxe2x80x9d or xe2x80x9coffxe2x80x9d. If the fax switch is set to xe2x80x9conxe2x80x9d, the call screening unit will also determine if the signal is a fax/computer signal. If the signal is a fax/computer signal, the call will be allowed to pass through. Thus, the user""s phone will only ring if the incoming call has a valid carrier signal, if a valid override code was entered by the caller, of if the call has a fax/computer signal and the fax switch is set to xe2x80x9con.xe2x80x9d
The call screening unit includes key pads for setting, changing, and deleting user stored override codes and an authorization or Personal Identification Code (PIC). It also includes a printer for printing the user stored and caller entered override codes and an LED display which displays the user stored and caller entered override codes. Whenever user stored override codes are changed, displayed, deleted, or printed, the call screening unit prompts the user for an authorization code or PIC. A valid PIC must be entered before override codes can be changed, displayed, deleted or entered. The user has a predetermined number of tries to enter a valid PIC when carrying out one of these functions. If, after this predetermined number of tries, a valid PIC is not entered, an alarm is sounded. The helps prevent unauthorized users from changing, displaying, deleting, or printing the user stored override codes.